https://docs.oracle.com/cd/E88353_01/html/E37846/sqrtl-3m.html
sqrtl - man pages section 3: Extended Library Functions, Volume 2
sqrt , sqrtf , sqrtl - square root function These functions compute the square root of their argument x .
man pagesextended librarysectionfunctionsvolume
https://cygwin.com/pipermail/cygwin/2020-October/246606.html
sqrtl behavior inconsistent with sqrt and sqrtf
behaviorinconsistentsqrt